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AERODROMEWEATHERREPORTANDFORECASTDECODE
Identifier
METAR is used to identify routine observations (hourly or half-hourly) when
conditions are above specified levels. SPECI is used to identify special
observations, i.e. observationswhen conditions are below specified criteria,
orwhen there have been significant changes since the previous report.
SPECI is also used to identify observations reported10minutes following an
improvement to aboveSPECI conditions.
TTFMETAR or TTFSPECI is used to identifyMETARor SPECI towhich a
trend forecast is appended. The use of this identifier is restricted to those
locations that issue trend forecasts.
TAF, TAFAMD, TAFCOR, TAF... CNL, TAF ... NIL andPROV TAF areused
to identifyAerodrome Forecast, AmendedAerodromeForecast, Corrected
Aerodrome Forecast, CancelledAerodrome Forecast, Nil Aerodrome Forecast
andProvisional Aerodrome Forecast respectively.
Location
The location is indicatedby the ICAO location indicator, theplacename, or the
approved abbreviation.
IssueTime
Theorigination date/time of TAF andMETAR/SPECI is given inUTCusing a
six figure group followed by the code Z (for UTC).
ValidityPeriod
The validity period of a TAF is given inUTC in the format ddhh/ddhh, where
ddhh is the day ofmonth and hour, e.g. 0100/0206 is a validity period from00
UTC on the 1st until 0600UTC on the 2nd.
AUTO
This groupwill be includedwhen theMETAR/SPECI contains only automated
observations, whichmay include visibility, presentweather, and cloud.
When theAutomaticWeather Station (AWS) includes sensors for horizontal
visibility, presentweather and cloud, theAUTO reportwill include the
parameters from these sensors in the “body of themessage” (where
previously onlymanually observed visibility, presentweather and cloud data
were included).
2 – me t eorology
aerodrome forecasts and reports